Myocarditis is an inflammation of the myocardium, the middle layer of the heart wall. Myocarditis is usually caused by a viral infection. Signs and symptoms of myocarditis include chest pain, heart failure and abnormal heart rhythms.

If myocarditis becomes severe, the pumping action of your heart weakens, and your heart won't be able to supply the rest of your body with enough blood. Clots also could form in your heart, leading to a stroke or heart attack.

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